Stator for electric rotating machine

Abstract

A stator includes a stator core and a multi-phase stator coil distributedly wound on the stator core. The stator core includes a plurality of teeth and a yoke having a plurality of grooves. Each of the teeth has a press-fit portion, which is press-fitted in a corresponding one of the grooves of the yoke, and a main body portion extending from the press-fit portion in a direction away from the corresponding groove. The press-fit portion has a pair of contact surfaces which are both in contact with a bottom surface of the corresponding groove and away from each other in a width direction of the tooth. Further, (a+b)≦e/2, where a and b respectively represent widths of the contact surfaces of the press-fit portion, and e represents a width of the main body portion at a press-fit portion-side end of the main body portion.

1 . A stator for an electric rotating machine, the stator comprising:
 a stator core; and   a multi-phase stator coil distributedly wound on the stator core,   wherein   the stator core includes a plurality of teeth and a yoke that is separately formed from the teeth and magnetically connects the teeth,   the yoke has a plurality of grooves formed in a surface thereof,   each of the teeth has a press-fit portion, which is press-fitted in a corresponding one of the grooves of the yoke, and a main body portion that extends from the press-fit portion in a direction away from the corresponding groove,   the press-fit portion has a pair of contact surfaces which are both in contact with a bottom surface of the corresponding groove of the yoke and away from each other in a width direction of the tooth, and   the following dimensional relationship is satisfied:
   ( a+b )≦ e/ 2,
 
   
       where a and b respectively represent widths of the contact surfaces of the press-fit portion, and e represents a width of the main body portion at a press-fit portion-side end of the main body portion. 
     
     
         2 . The stator as set forth in  claim 1 , wherein the following dimensional relationship is further satisfied: a=b. 
     
     
         3 . The stator as set forth in  claim 1 , wherein for each of the teeth of the stator core, the following dimensional relationship is further satisfied:
   0.8≦ d/e≦ 1.2,
   
       where d represents a width of the press-fit portion at its end facing the bottom surface of the corresponding groove of the yoke. 
     
     
         4 . The stator as set forth in  claim 1 , wherein for each of the teeth of the stator core, the contact surfaces are first contact surfaces of the press-fit portion,
 the press-fit portion also has a pair of second contact surfaces which are respectively in contact with an opposite pair of side surfaces of the corresponding groove of the yoke, and the following dimensional relationship is further satisfied:
   0°<α<45°,
 
   
       where α represents an angle between each of the second contact surfaces and a centerline of the tooth, the centerline being an imaginary line which bisects the tooth in the width direction thereof. 
     
     
         5 . The stator as set forth in  claim 1 , wherein each of the grooves of the yoke has a neck part in the vicinity of an open end of the groove which opens on the surface of the yoke, and
 for each of the teeth of the stator core, the press-fit portion of the tooth has a neck part that is press-fitted to the neck part of the corresponding groove of the yoke, and   wherein   for each of the teeth of the stator core, the following dimensional relationship is further satisfied:
   W1<W2, 
   where W 1  represents a width of the main body portion at its end on the opposite side to the press-fit portion, and W 2  represents a width of the press-fit portion at its neck part.   
     
     
         6 . The stator as set forth in  claim 1 , wherein the following dimensional relationship is further satisfied:
   β1≦β2/2,
   
       where β 1  represents a depth of each of the grooves of the yoke, and β 2  is a radial thickness of the yoke.